Silencer with expansion chambers and manufacturing method thereof

ABSTRACT

Firearm silencers and processes for the production thereof in a layered structure as one single-piece body having at least one expansion chamber.

FIELD

The invention at hand relates to the field of silencers for firearms.

BACKGROUND

Silencers for firearms serve the purpose of reducing the noise emissionsresulting from the expansion of gases escaping from the barrel's muzzle,the so-called muzzle blast. Silencers are usually attached by beingscrewed on by a thread of the barrel or tube of the gun. Alternatively,they are connected factory-set with the weapon.

The noise reduction is desirable in some areas of use: examples of usagepurposes of silencers include hunting in populated areas or avoidingalarming the wild animals. In addition, they preserve the hearing healthof police and military forces.

Conventional silencers share some common characteristics. For one, theyconsist of several individual pieces, which are held together by asleeve or a piece of pipe. These items are typically made of differentmaterials. In addition, traditional silencers are turned and milled bymeans of conventional manufacturing processes.

A traditional silencer is, for example, known from the German patent DE17 03 420 B2. A multi-part silencer, which has several expansionchambers divided by inserts, is disclosed there. In particular, severalinserts which support each other are surrounded and held together by apiece of pipe.

The above features of conventional silencers have some disadvantages.The construction with several individual items and partially differentmaterials, drives up both the production costs and the weight. Aconstruction involving several individual parts is also susceptible todeveloping interference vibrations and assembly failures. Production bymeans of turning and milling limits the geometry of the silencer, inparticular the geometry of the sound-absorbing elements.

SUMMARY

The invention at hand is based on the object of, at least partially,reducing the above-mentioned disadvantages of conventional silencers.

The above problem is solved by a device and a production method inaccordance with independent patent claims. The dependent claims describepreferred versions. The invention consists of a firearm silencer, inshort: silencer.

The device according to the invention includes a main body. This mainbody is formed as a single-piece body extending along and around acentral longitudinal axis, and defines at least one expansion chamber,which is formed coaxially with the central longitudinal axis.

A production method for the layered, i.e. layer-wise structure is toachieve the object of the invention to provide a compact, light,material and/or cost saving construction and/or the development of newgeometries and designs according to the invention.

The central longitudinal axis preferably matches a path of a projectileshot from an attached gun.

The main body, which can be produced as one single piece, is a singlepiece in that it is preferably made of a homogeneous material and/orrequires no assembly steps involving several components, as is the casewith conventional silencers.

The expansion chambers are hollow spaces formed in the main body whichallow room for the expansion of gases. These gases escape from a muzzleof a firearm. Without a silencer mounted on the muzzle, the uncontrolledexpansion of these gases leads to the muzzle blast. The silencersaccording to the invention include at least one expansion chamber whichis formed to be coaxial to the central longitudinal axis. Expansionchambers can be designed as sound guide chambers. The term expansionchamber should not be understood as a description of a particulargeometry. In general, co-axial bodies, chambers, etc. do not necessarilyhave to be rotationally symmetrical around the corresponding axis, inthe sense of the present invention. Expansion chambers aligned coaxiallyto the central longitudinal axis result in an at least partly structuralalignment.

Preferably, the main body defines at least two expansion chambers whichare formed coaxially in relation to the central longitudinal axis.

The main body is preferably also made of layers in direction of thecentral longitudinal axis.

The main body can preferably be produced using one of the followingproduction method of producing in the direction of a centrallongitudinal axis: a 3D printing method, a stereo-lithography method, aselective laser sintering method, a casting, or a forming method. Aselective laser sintering method is particularly preferred during whichmaterials, for example a metal, is selectively sintered by a laser, i.e.bound together and compacted. This procedure is preferably carried outin layers. After sintering the material of one layer, the unsintered rawmaterial of each following layer is applied and then laser-sintered inturn. Due to symmetry and structural considerations, it is especiallyadvantageous to form the silencer layer by layer along the direction ofa central longitudinal axis, which corresponds to the firing channel.

The main body preferably defines at least one of the following elements:an outer wall, which limits at least one expansion chamber on theoutside; walls aligned coaxially along the central longitude which limitat least one expansion chamber; bars, at least some of which areextending perpendicular to the central longitudinal axis; supportingstructures at least some of which extend coplanar to the centrallongitudinal axis; a thread for connection to the barrel or an interfacefor connection to the barrel of the firearm; a muzzle opening; a firingchannel extending along the central longitudinal axis through the mainbody.

An exterior wall can serve for an external presentation of thesuppressor marked with a trade mark or company logo. In addition, it canprovide easier handling for the user. The user grasps the external wallto attach the silencer onto a firearm.

Walls, bars and support structures respectively can each serve toprovide stable statics and/or to direct the flow of the expanding gases.

A thread can provide the simple, rapid, gas leak-proof and/or secureconnection with a firearm. This connection can be made either directlyor indirectly. This connection can be made directly with the barrel ofthe firearm. Alternatively, or in addition, this connection can beachieved indirectly using a suitable adapter or a different interface toconnect the silencer with the barrel of a firearm, such as, for example,a quick-clamp. A muzzle opening serves for the projectiles to leave thesilencer. A firing channel provides an unobstructed path for theprojectiles and a primary direction of flow of expanding gases.

It is preferable for at least one of the expansion chambers to becurved. This allows, among others things, redirections and/ortrajectories of the expansion chambers with twists, curves, etc. Thishas several advantages, according to the invention. For the same lengthof the silencer, longer effective lengths of expansion chambers becomepossible. Turbulence is reinforced by strong curvature, which can resultin a strong reduction of the muzzle blast. Long expansion chambers alsoincrease the limiting surface of the expansion chamber, thereby alsostrengthening the absorption effect.

With this invention, curvatures of the expansion chambers can bedesigned in various forms as desired. These curvatures may includecomponents or portions in one or more of the following directions:azimuth direction, radial direction, or axial direction. Theabove-mentioned directions refer preferably to silencers beingessentially cylindrical. The skilled person is well-acquainted withcylindrical geometries for use with cylindrical coordinate systems.Here, the three dimensions are described respectively using anazimuthal, radial or axial unit vector. A curvature can be expressedlocally by a tangent vector. Within the cylindrical coordinate system,the tangential vector can be deconstructed into components or portionswith regard to said unit vectors. Accordingly, a curvature component inazimuth direction is oriented around the central longitudinal axis.

A curvature component in radial direction is oriented away from thecentral axis. A curvature component in axial direction is oriented alongor parallel to the central longitudinal axis. Exemplary curvaturesoriented in one or more of the above directions are discussed in theversion examples.

Alternatively or in addition, at least one of the expansion chambers canhave a tapering and/or widening at its cross section. According to theinvention, tapering and/or widening of the cross-section can be used tocontrol the expansion of gases. They lead to increased or reduced flowvelocities, and this can have impact on the damping of the muzzle blast.

Preferably, one or more expansion chambers can open into in a soundabsorption area. Such a sound absorption area can have various forms.According to the invention, forms of sound absorption areas includeareas made porous and areas having a foam structure. In addition oralternatively, a sound absorption area can take the shape of a bag-likeend of an elongated expansion chamber. The expansion energy of theexpanding gas or noise generated by the gas expansion is absorbed whollyor in part by such sound absorption areas. The ratio of absorbentsurface to expansion volume can be optimized by having the expansionchambers branch out and/or or having long expansion chambers.

Preferably, one or more expansion chambers can open toward an outer wallof the main body. Such openings to an outer wall allow some of theexpanding gases to escape into the environment after passing through oneor more expansion chambers. By decreasing the expansion energy in theexpansion chamber(s) (through absorption, turbulence, etc.), the blastresulting from the gases flowing out is at least reduced or evencompletely suppressed. Openings of expansion chambers towards an outerwall of the main body can be formed at various locations along the outerwall. In particular, it is conceivable, for example, given anessentially cylindrical main body, to provide these openings at one orboth faces of the cylinder and/or on the mantle surface of the cylinder.

It is preferred that one or more expansion chambers can be open towardsthe central longitudinal axis. This opening can be formed so that itleads to the firing channel. In particular, this opening may be situatedopposite the firing direction. According to the invention, such apreferred design may allow to increasingly mitigate the expanding gasesby repeatedly passing them through the—or the same—expansion chambers.

In addition or alternatively, several of the expansion chambers cancombine/merge along their extensions. This can be advantageous, forexample, if one or a few expansion chambers have openings to an outerwall or to the central longitudinal axis. In this or other cases, otherexpansion chambers can combine/merge along their extensions with theexpansion chambers with openings, so that the gases expanding thereincan also escape through these openings. This can lead, among otherthings, to a more compact design and/or weight saving compared with adesign without combining/merging of expansion chambers.

In addition or alternatively, at least one of the expansion chambers canbranch out along its extension. This is advantageous, for example, ifthe expanding gases in a single expansion chamber should be directed totwo locations. These locations may include, among others, one or more ofthe above-cited sound absorption areas, one or more of the above-citedopenings to the outer wall, and/or one or more openings to the centrallongitudinal axis. For example, the branching of an expansion chamber,where a branch has an opening to the outer wall, and a second branch hasan opening to the central longitudinal axis, is very advantageous. Othercombinations of the above locations are apparent to the skilled personand are as well according to the invention.

Further, preferably expansion chambers are arranged as helices coaxialto the central longitudinal axis. Particularly, two expansion chamberscan be arranged as double helix, three expansion chambers as triplehelix, etc.

Furthermore, preferred is an arrangement of expansion chambers, whereseveral of them surround each other each other in a concentric layout.Thus, a compact and material-saving construction can be achieved also.For example, a broad range of distribution of expansion chambers ofdifferent lengths can achieve such a nested construction. As a result,the routes or volumes, along which the expanding gases pass through inthe expansion chambers, have a broad range of distributions. In additionor alternatively, possible recirculation towards the centrallongitudinal axis can be made in reverse order. More information will beprovided in the following, for example, by means of preferred versions.

A method according to the invention of producing a firearm silencerincludes forming material along a central axis for one single-piece mainbody, so that at least one expansion chamber is coaxially formed withregard to the central longitudinal axis.

It is preferred that the formation of the material is carried out layerby layer along the central longitudinal axis. It is particularlypreferred that the formation of each layer is carried out perpendicularto the central longitudinal axis in a two-dimensional grid. It isespecially preferred that this two-dimensional grid extends alongCartesian or polar coordinates.

In addition or alternatively, the production is carried out using asingle raw material. This raw material is particularly preferred to be ametal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a cross-section, which is parallel to the central axis, ofa first version of the invention.

FIG. 1B shows a cross-section, which is parallel to the central axis, ofthe first version of the invention.

FIG. 2A shows a cross-section, which is parallel to the central axis, ofa second version of the invention.

FIG. 2B shows a cross-section, which is parallel to the central axis, ofthe second version of the invention.

FIG. 3A shows a cross-section, which is parallel to the central axis, ofa third version of the invention.

FIG. 3B shows a cross-section, which is parallel to the central axis, ofthe third version of the invention.

FIG. 4A shows a cross-section, which is parallel to the central axis, ofa fourth version of the invention.

FIG. 4B shows a cross-section, which is parallel to the central axis, ofthe fourth version of the invention.

FIG. 5A shows a cross-section, which a parallel to the central axis, ofa fifth version of the invention.

FIG. 5B shows a cross-section, which is parallel to the central axis, ofthe fifth version of the invention.

DETAILED DESCRIPTION

Hereafter, the invention will be discussed in more detail based on theversions presented in the illustrations; in all illustrations,essentially functionally identical elements will have the same referencenumeral.

FIGS. 1A and 1B shows a first version of a silencer 10 according to theinvention. FIG. 1A provides a top view of a longitudinal section of thesilencer 10, and FIG. 1B the same longitudinal section of the silencer10 in foreshortened view. Both partial illustrations show the samefeatures that are consequently also marked with the same referencenumerals and will likewise be described below.

The silencer 10 comprises a main body 12. The main body 12 can bemanufactured along a central longitudinal axis 14.

The main body 12 is essentially cylindrical and defines, by its shapeand geometry, among other things, an outer wall 30. The outer wall 30essentially describes a cylinder barrel mantle, two faces with cut-outsfor a thread 37 and a muzzle opening 39, as well as rounded edges at thetransition between the cylinder mantle and face surfaces.

The thread 37 is of a screw type for being connected either indirectlyor directly with a barrel of a gun. The thread 37 is connected to themuzzle opening 39 by a firing channel that extends through the main body12 and along the central longitudinal axis 14. The inner structures, inparticular the expansion chambers 20, 22, 24, 26 of the silencer 10, aredefined by the main body 12; these expansion chambers serve to reducethe muzzle blast of a projectile fired by this firearm.

For this purpose, the illustrated version provides, e.g., theinvention's features of walls, support structures, tapering of expansionchambers, curvatures of expansion chambers, merging of expansionchambers, expansion chambers surrounding each other, as well as openingsto the firing channel.

The walls 31, 32 serve as exemplary illustration of walls extendingcoaxially to the central longitudinal axis, and they are defined by themain body 12 and limit the expansion chambers. For example, the wall 31limits the expansion chamber 26 toward the outside. Wall 32 limits theexpansion chamber 24 toward the outside and the expansion chamber 26toward the inside. The other depicted expansion chambers 20, 22 havewalls which are not separately named here for reasons of economy ofrepresentation.

The exemplary support structures 35, 36, each of which extendsrespectively in a manner that is coplanar to the central longitudinalaxis, serve to stabilize statics and/or to direct the flow direction ofexpanding gases.

The expansion chambers 20, 22, 24, 26 also show changes in their crosssections, especially taperings.

Further, there is a curvature of the expansion chamber at the transitionbetween the muzzle-side part of each expansion chamber and thethread-side part of each expansion chamber. The above-mentioned featuresof tapering and curvature of the expansion chambers are designed toimprove noise reduction.

Further, the expansion chambers 20, 22, 24, 26 are open toward thefiring channel. The common opening to the firing channel is marked withreference numeral 44. These expansion chambers merge in close proximityto this opening. In the case at hand, the merging of multiple expansionchambers serves to produce a single opening 44.

Further, the illustrated exemplary version shows that the expansionchambers 20, 22, 24, 26 surround each another. This construction, whichresembles Matryoshka dolls or nested assemblies, leads to a compactconstruction and expansion chambers having different lengths with theresulting differently sized volumes. In the case at hand, expansionchamber 26 is the outermost expansion chamber, whereas expansion chamber20 forms the innermost expansion chamber.

In operation, the silencer 10 is connected to the barrel of a firearmeither indirectly or directly with the help of the thread 37 (notshown). After a projectile has been fired, it passes through the firingchannel along the central longitudinal axis, through the main body andto the muzzle opening 39. In addition, gases travel this route and intothe suppressor. According to the invention, some of these gases thenexpand in the expansion chambers, whereby their expansion can bepartially controlled to largely prevent an explosive expansion, whichwould result in a muzzle blast. The gases thus flow through the firingchannel from the thread 37 to the muzzle opening 39 and, during thecourse of this flow, are partially absorbed in each of the expansionchambers 20, 22, 24, 26. The respective part flowing through one of theexpansion chambers is re-directed along this expansion chamber oppositethe firing direction to the opening 44, where a repeated flow beginsthrough the firing channel. This redirection can be carried out multipletimes. Thus, only a fraction of the expanding gases gradually escapes ineach instance through the muzzle opening 39, and, according to theinvention, there is no, or at the very least a significantly reduced,muzzle blast.

FIGS. 2A and 2B shows a second exemplary version of a silencer 10according to the invention. FIG. 2A shows the top view of a longitudinalsection of the silencer 10, and FIG. 2B shows the same longitudinalsection of the silencer 10 in foreshortened view. Both partialillustrations display the same features that are consequently alsomarked with the same reference numerals and will likewise be describedbelow.

The silencer 10 comprises a main body component 12. The main bodycomponent 12 can be manufactured along a central longitudinal axis 14.

The main body component 12 is essentially cylindrical and defines, byits shape and geometry, among other things an outer wall 30. The outerwall 30 is essentially made up of a cylinder mantle, two faces withcut-outs for a thread 37 and a muzzle opening 39, as well as roundededges at the transition between the cylinder mantle and face surfaces.

The screw-type thread 37 is connected either indirectly or directly withthe barrel of a gun. The thread 37 is connected to the muzzle opening 39by a firing channel that extends through the main body 12 and along thecentral longitudinal axis 14. The inner structures, in particular theexpansion chambers 20, 22, 24, 26 of the silencer 10, are defined by themain body/component 12; these expansion chambers serve to reduce themuzzle blast of a projectile fired by this firearm.

For this purpose, the illustrated version provides, among other things,the invention's features of the walls, support structures, tapering ofexpansion chambers, curvatures of expansion chambers, expansion chamberssurrounding each other, as well as openings to the firing channel.

The walls 31, 32 serve as exemplary illustrations of walls extendingcoaxially to the central longitudinal axis and they are defined by themain body 12 and limit the expansion chambers. For example, the wall 31limits the expansion chamber 22 toward the outside, and the expansionchamber 20 toward the inside. Wall 32 limits the expansion chamber 24toward the outside and the expansion chamber 26 toward the inside. Theother illustrated expansion chambers also have walls that are notindividually named for reasons of economy of representation.

The exemplary support structures 35, 36, each of which extendsrespectively in a manner that is coplanar to the central longitudinalaxis, serve to stabilize statics and/or to direct the flow direction ofexpanding gases.

The expansion chambers 20, 22, 24, 26 also show changes in their crosssections, especially taperings. Each of the expansion chambers show apart extending essentially diagonally to the central longitudinal axis14 in a relatively large cross-section, as well as one part extendingessentially parallel to the central longitudinal axis 14 in a relativelysmall cross-section. A reduction of the cross-section, i.e. tapering, isthus located at the transition point between the two said parts.

Further, there is a curvature of the expansion chamber at the transitionbetween the part of each expansion chamber which is essentially diagonalto the central longitudinal axis 14 and the part of each expansionchamber which is parallel to the central longitudinal axis 14. In thecase at hand, the curvature has predominantly axial components, as wellas, in part, radial and azimuthal components. The azimuthal, i.e.helix-like components are determined here among other things by the formand pathway of supporting structures. Two examples of support structureshave been assigned the reference numerals 35, 36. The above-mentionedfeatures of tapering and curvature of the expansion chambers are forimproving noise reduction.

Further, the expansion chambers 20, 22, 24, 26 open into the firingchannel. Each expansion chamber has an individual opening to the firingchannel. The one for the expansion chamber 24 is referred to by itsreference numeral 44.

Further, the illustrated exemplary version shows that the expansionchambers 20, 22, 24, 26 surround each another. This method ofconstruction, along the lines of Matryoshka or nested arrangement servesto keep construction compact and to allow the expansion chambers to beof varying lengths. In the case at hand, expansion chamber 20 is theoutermost expansion chamber, whereas expansion chamber 26 forms theinnermost expansion chamber.

In operation, the silencer 10 is attached to the barrel of a firearm(not shown) by means of the thread 37. After a projectile has beenfired, it passes through the firing channel along the centrallongitudinal axis, through the main body and to the muzzle opening 39.In addition, gases travel this route and into the suppressor. Accordingto the invention, some of these gases then expand in the expansionchambers, whereby their expansion can be partially controlled to largelyprevent an explosive expansion, which would result in a muzzle blast.

The gases thus flow through the firing channel from the thread 37 to themuzzle opening 39 and, during the course of this flow, are partiallyabsorbed in each of the expansion chambers 20, 22, 24, 26. Therespective part flowing through one of the expansion chambers, isdirected, along the expansion chamber and along the firing direction, toan opening, e.g. opening 44 in the case of expansion chamber 24, where apartially backward-directed flow through the firing channel begins. Thusonly a fraction of the expanding gases gradually escapes in eachinstance through the muzzle opening 39, and conforming to the invention,there is no, or at the very least a significantly reduced, muzzle blast.

FIGS. 3A and 3B shows a third version of a silencer 10 according to theinvention. FIG. 3A shows the top view of a longitudinal section of thesilencer 10 and FIG. 3B the same longitudinal section of the silencer 10in foreshortened view. Both partial illustrations show the same featuresthat are consequently also marked with the same reference numerals andwill likewise be described below.

The silencer 10 comprises a main body 12. The main body 12 can bemanufactured along a central longitudinal axis 14.

The main body/component 12 is essentially cylindrical and defines, byits shape and geometry, among other things, an outer wall 30. The outerwall 30 essentially includes a cylinder mantle, two faces with cut-outsfor a thread 37 and a muzzle opening 39, as well as rounded edges at thetransition between the cylinder mantle and face surfaces.

The screw-type thread 37 is connected either indirectly or directly withthe barrel of a gun. The thread 37 is connected to the muzzle opening 39by a firing channel that extends through the main body 12 and along thecentral longitudinal axis 14. The inner structures, in particular theexpansion chambers 20, 22, 24, 26 of the silencer 10, are defined by themain body/component 12 and serve to reduce the muzzle blast of aprojectile fired by this firearm.

The illustrated exemplary version provides, for this purpose, amongother things, the invention's features of walls, support structures,tapered expansion chambers, curved expansion chambers, branchingexpansion chambers, openings to the firing channel, openings to theouter wall, sound absorption areas, as well as expansion chamberssurrounding each other.

The walls 31, 32 serve as an exemplary illustration of walls extendingcoaxially to the central longitudinal axis, which are defined by themain body 12 and limit the expansion chambers. The other illustratedexpansion chambers also have walls that are not individually named forreasons of economy of representation.

The exemplary support structures 35, 36, each of which extendsrespectively in a manner that is coplanar to the central longitudinalaxis, serve to stabilize statics and/or to direct the flow direction ofexpanding gases.

The expansion chambers 20, 22, 24, 26 also show changes in their crosssections, especially taperings. Each of the expansion chambers has apart which extends essentially perpendicularly to the centrallongitudinal axis 14 and has a relatively large cross section, as wellas a part that is essentially parallel to the central longitudinal axis14 and has a relatively small cross section. A reduction of thecross-section, i.e. a tapering is thus located at the transition pointbetween the two said parts.

Further, a curvature of every expansion chamber is located at thetransition between the part of each expansion chamber essentiallyperpendicular to the central longitudinal axis 14 and the part of eachexpansion chamber which is parallel to the central longitudinal axis 14.In the case at hand, the curvature has predominantly axial and azimuthalcomponents, and in part some radial components. Two examples of supportstructures have been assigned the reference numerals 35, 36. Theabove-mentioned features of tapering and curvature of the expansionchambers are for improving noise reduction.

Further, the expansion chambers have branches, so that the gasesexpanding in them can flow to different locations. These locationsinclude opening to the firing channel, openings to the outer wall, aswell as sound absorption areas. In particular, the expansion chambers20, 22, 24, 26 respectively open towards the firing channel. Eachexpansion chamber has an individual opening to the firing channel. Theone for the expansion chamber 24 is referred to by its reference numeral44. Further, the expansion chambers 20, 22, 24, 26 are open to the outerwall. Reference numerals 42, 43 refer to two exemplary openings. Also,some expansion chambers have sound absorption areas. Reference sign 40refers to an exemplary sound absorption area.

Further, from the illustrated exemplary version it can be seen that theexpansion chambers 20, 22, 24, 26 surround one another. This method ofconstruction, along the lines of Matryoshka or nested arrangement,serves to keep construction compact and to allow the expansion chambersto be of varying lengths. In the case at hand, expansion chamber 26 isthe outermost expansion chamber, whereas expansion chamber 20 forms theinnermost expansion chamber.

In operation, the silencer 10 is attached to the barrel of a firearm(not shown) by means of the thread 37. After a projectile has beenfired, it passes through the firing channel along the centrallongitudinal axis, through the main body and to the muzzle opening 39.In addition, gases travel this route and into the suppressor. Accordingto the invention, some of these gases then expand in the expansionchambers, whereby their expansion can be partially controlled to largelyprevent an explosive expansion, which would result in a muzzle blast.

The gases thus flow through the firing channel from thread 37 to muzzleopening 39 and, during the course of this flow, are partially absorbedin each of the expansion chambers 20, 22, 24, 26.

The respective part flowing through one of the expansion chambers isdirected along this expansion chamber opposite to the firing direction.These gases, which expand in the expansion chambers, encounterbranchings and mergings. On the one hand, the expansion chambers 20, 22,24, 26 merge so that the gases flow into a common area. On the otherhand, this common space branches out. The expanding gases flow partly toa sound absorption area 40, partly to one of several openings 42, 43 inthe outer wall 30, or to one of several openings 44, 45 to the firingchannel. Thus only a fraction of the expanding gases gradually escapesin each instance through the muzzle opening 39, and, according to theinvention, there is no, or at the very least a significantly reduced,muzzle blast. A part of the expanding gases passes through one of theopenings 42, 43 from the silencer. Some of the expanding gases onceagain, or repeatedly, are directed through one of the openings 44, 45through the firing channel. Further, some of the expansion energy isabsorbed in sack-like cul-de-sacs in the expansion chambers, i.e. thesound absorption area 40. Due to the large number of curvatures,taperings/widenings and branches, turbulence also arises in the gases'flow behavior, leading to a further expansion energy dissipation.

FIGS. 4A and 4B shows a fourth version of the silencer 10. According tothe invention, FIG. 4A shows the top view of a longitudinal section ofthe silencer 10 and FIG. 4B the same longitudinal section of thesilencer 10 in foreshortened view. Both partial illustrations show thesame features that are consequently also marked with the same referencenumerals and will likewise be described below.

The silencer 10 comprises a main body 12. The main body 12 can bemanufactured along a central longitudinal axis 14.

The main body 12 is essentially cylindrical and defines, by its shapeand geometry, among other things, an outer wall 30. The outer wall 30essentially includes a cylinder mantle, two faces with cut-outs for athread 37 and a muzzle opening 39, as well as rounded edges at thetransition between the cylinder mantle and face surfaces.

The screw-type thread 37 is connected either indirectly or directly withthe barrel of a gun. The thread 37 is connected to the muzzle opening 39by a firing channel that extends through the main body 12 and along thecentral longitudinal axis 14. The inner structures, in particular theexpansion chambers 20, 22, 24, 26 of the silencer 10, are defined by themain body 12; and serve to reduce the muzzle blast of a projectile firedby this firearm.

For this purpose, the illustrated exemplary version provides, interalia, the invention's features of curved expansion chambers, taperingsand widenings, support structures, as well as openings to the firingchannel.

The expansion chambers 20, 22, 24, 26 exhibit changes in their crosssection. As seen from the top view, each of the expansion chambers hasan essentially u-shaped longitudinal section. Each of the legs of the Ushows a different cross-section. Thus, on the one hand, a curvature,and, on the other hand, taperings, or widenings are provided at thetransition between the respective legs. In this case, the curvaturefeatures predominantly axial and radial components.

Two exemplary support structures are assigned the reference numerals 35,36. The above-mentioned characteristics of taperings/widenings andcurved expansion chambers serve to improve noise reduction.

Further, the expansion chambers 20, 22, 24, 26 open to the firingchannel. Each expansion chamber has an individual opening to the firingchannel. The one for the expansion chamber 24 is referred to by itsreference numeral 44.

Further, in the exemplary version shown, it is evident that in thepresent case the expansion chambers 20, 22, 24, 26 do not surround eachother, but are arranged sequentially along the firing direction.

The exemplary support structures, 35, 36, that at least partly extend ina coplanar manner to the central longitudinal axis, serve to stabilizestatic and/or the direction of the flow of the expanding gases.

In operation, the silencer 10 is attached to the barrel of a firearm(not shown) by means of the thread 37. After a projectile has beenfired, it passes through the firing channel along the centrallongitudinal axis, through the main body and to the muzzle opening 39.In addition, gases travel this route and into the suppressor. Accordingto the invention, some of these gases then expand in the expansionchambers; whereby their expansion can be partially controlled to largelyprevent an explosive expansion, which would result in a muzzle blast.

The gases thus flow through the firing channel from the thread 37 to themuzzle opening 39 and, during the course of this flow, are partiallyabsorbed in each of the expansion chambers 20, 22, 24, 26. Therespective part of gases flowing through one of the expansion chambersis directed along this expansion chamber. Along their path in theexpansion chambers, the expanding gases encounter curvatures andcross-section changes. Thus, only a fraction of the expanding gasesgradually escapes in each instance through the muzzle opening 39, and,according to the invention, there is no, or at the very least asignificantly reduced, muzzle blast. Due to the large number ofcurvatures, taperings/widenings and branches, turbulence also arises inthe gases' flow behavior, leading to the expansion energy dissipatingeven further.

FIGS. 5A and 5B shows a fifth version of a silencer 10 according to theinvention. FIG. 5A shows the top view of a longitudinal section of thesilencer 10, and FIG. 5B the same longitudinal section of the silencer10 in foreshortened view. Both partial illustrations show the samefeatures that are consequently also marked with the same referencenumerals and will likewise be described below.

The silencer 10 comprises a main body 12. The main body 12 can bemanufactured along a central longitudinal axis 14.

The main body 12 is essentially oblong and defines by its shape andgeometry by, among other things, an outer wall 30. However, the outerwall 30, in contrast to the above exemplary version, does not describe acylindrical shape in the case at hand. Also, central longitudinal axis14 does not run through the geometric center, but, instead, is offsetupwards. This exemplary version illustrates the structural flexibilityof the invention, something which goes hand in hand with its productionaccording to the invention.

For this purpose, the illustrated exemplary version provides, amongother things, the invention's features of tapering of expansionchambers, curvatures of expansion chambers, merging of expansionchambers, expansion chambers surrounding each other, sound absorbingareas and openings to the outer wall.

The tapering of expansion chambers is illustrated by means of expansionchambers 24, 26. The use of multiple curved expansion chambers isrepresented by the expansion chamber 22, resulting in an unusually longexpansion chamber. A merging of two expansion chambers is shown asexample for the expansion chambers 20 and 22. Further, it is evidentfrom the illustrated exemplary version that the expansion chamber 22surrounds the expansion chambers 24 and 26. The use of sound absorptionareas is demonstrated in the example of the expansion chamber 26 withits sound absorption area 40. Expansion chamber 22 also includes anopening 42 to the outer wall 30 of the main body 12.

In operation, the silencer 10 is connected (not shown) to the firearm bya tube placed in the area of the expansion chamber 20. After aprojectile is fired, it passes along the central longitudinal axisthrough the firing channel, through the main body and then to the muzzleopening 39. In addition, gases travel this route and into thesuppressor. According to the invention, some of these gases then expandin the expansion chambers and their expansion can be partiallycontrolled to largely prevent an explosive expansion, which would resultin a muzzle blast.

The gases thus flow through the firing channel to the muzzle opening 39,and, along this way are partially absorbed by each of the expansionchambers 20, 22, 24, 26. Thus, only a fraction of the expanding gasesgradually escapes through the muzzle opening 39 and the opening 42 tothe outer wall; and in accordance with the invention, there is no, or atthe very least a significantly reduced, muzzle blast.

REFERENCE NUMERALS

-   Firearm silencer 10-   Main body 12-   Longitudinal axis 14-   Expansion chamber 20, 22, 24, 26-   Outer wall 30-   Wall 31, 32-   Bars 33, 34-   Support structure 35, 36-   Thread 37-   Muzzle Opening 39-   Sound absorption area 40-   Opening to the outer wall 42, 43-   Opening to the firing channel 44, 45

What is claimed is:
 1. A firearm silencer comprising a main body, whichis formed and a single-piece body extending along and around a centrallongitudinal axis, and defines at least one expansion chamber formedcoaxially in relation to the central longitudinal axis.
 2. The silenceraccording to claim 1, wherein the main body of the silencer is formed inlayers in the direction of the central longitudinal axis.
 3. Thesilencer according to claim 1, wherein the silencer is producible by oneof the following production processes: 3D printing process; astereo-lithography method; a selective laser sintering process; acasting process; and a forming process.
 4. The silencer according toclaim 1, wherein the main body of the silencer is defined by at leastone of the following features: an outer wall which limits, toward theoutside, the at least one expansion chamber; a muzzle opening; and afiring channel that extends through the main body in the direction ofthe central longitudinal axis.
 5. The silencer according to claim 1,wherein the main body of said silencer is defined by at least one of thefollowing features: walls extending coaxially in relation to the centrallongitudinal axis, which walls limit at least the one expansion chamber;bars at least partly extending perpendicular to the central longitudinalaxis; supporting structures at least partly extending in coplanar mannerin relation to the central longitudinal axis; and a thread for direct orindirect connection with at least one of a barrel of a firearm and aninterface for attachment to a barrel of a firearm.
 6. The silenceraccording to claim 1, wherein at least one of the expansion chambers iscurved.
 7. A silencer according to claim 1, wherein the curvatureincludes components in at least one of the following directions:curvature component in azimuthal direction; curvature component inradial direction; and curvature component in axial direction.
 8. Asilencer according to claim 1, wherein at least one of the expansionchambers is tapered or widened in its cross section.
 9. A silenceraccording to claim 1, wherein at least one of the expansion chambersopens into a sound absorption area.
 10. A silencer according to claim 1,wherein at least one of the expansion chambers opens to an outer wall ofthe main body.
 11. A silencer according to claim 1, wherein at least oneof the expansion chambers opens into the firing channel or the centrallongitudinal axis.
 12. A silencer according to claim 1, wherein the mainbody defines at least two expansion chambers, which merge along theirextension.
 13. A silencer according claim 1, wherein at least one of theexpansion chambers branches out along its extension.
 14. A silenceraccording to claim 1, wherein the main body defines at least twoexpansion chambers which are arranged as coaxial helices along thecentral longitudinal axis.
 15. A silencer according to claim 1, whereinthe main body defines at least two expansion chambers, surrounding oneanother in concentric manner.
 16. A method of producing a firearmsilencer, wherein material for a single-piece main body of the firearmsilencer is formed along a central longitudinal axis, in such a mannerthat at least one expansion chamber is coaxially formed with regard tothe central longitudinal axis.
 17. The method according to claim 16,wherein the formation of the material is carried out layer-wise towardsthe central longitudinal axis.
 18. The method of claim 17, wherein theformation of each layer is carried out perpendicular to the centrallongitudinal axis two-dimensional grid pattern.
 19. The method of claim16, wherein the formation of material is carried out according to one ofthe following manufacturing processes: a 3D printing process; thestereo-lithography method; a selective laser sintering process; acasting process; and a forming process.
 20. The method of claim 16,wherein the producing is carried out by means of a process employs theuse of a single raw material.